not sure what this is...maybe tmj?

A couple days ago, I opened my mouth to take a bite of a sandwich & I felt something 'pop' in my jaw.

Since then, I have had some trouble clenching my jaw, chewing, etc. There also sounds like there is a clicking noise in that side when I chew.

I am not sure what type of dentist to see about this. I just visited my normal dentist about a week ago for an unrelated problem & I'm not sure if I should go back to see him about this. Should I wait to see if it clears up? Could it just be a muscle or something? Any ideas would be welcome!